Feasibility study on tidal barrier claims to solve most of Inner Harbour’s flood problems
A study produced through the creation and analysis of the results of a digital simulation model concluded that the installation of a tidal barrier at the entrance of the seaway between Inner Harbour and the Wanzai, Zhuhai area would be able to solve most of the issues regarding severe flooding caused by storm surge.
The conclusions of the study were presented yesterday in a session dedicated to the lawmakers at the Legislative Assembly.
Gao Wen Jie, a representative of the company that created the computer-simulation model and ran the study said that the results demonstrate the “contribution of the tidal barrier for drastically reducing the flooded areas in the Inner Harbour area.”
The study also modelled the impacts of the construction and operation of the tidal barrier on the surrounding areas at the South and East of the Peninsula and Northern part of Taipa, concluding that the works would not have a significant impact although they would cause a rise in sea level in those areas.
Gao said that the overall conclusions of the study support the construction of the tidal barrier and additionally propose that levees be raised or built in the South and the East sections of the Peninsula.
According to the same representative, the study involved a simulation of 25 situations in a total of 400 experiments.
It also proposes the barrier have gates high enough to support a water level rise to 3.85 meters – that is, seven centimeters higher than the maximum level reached during the passage of Typhoon Hato, with the whole structure being 5.5 meters above normal sea levels.
He also noted that to test the resistance of the gates, data from Typhoons Hato and Mangkut were used.
The Public Works Bureau (DSOP) director Lam Wai Hou remarked that the construction of the tidal barrier would only be considered as long-term works for flood prevention, noting that broader efforts are currently being directed into short and medium-term works that include the installation of box culvert and stormwater lift stations in several locations, including at the Inner Harbour and Fai Chi Kei coastal areas.
Lam noted that some of these are already being built or have concluded, with work on the section between the Rua do Dr. Lourenco Pereira Marques and Rua das Lorchas reaching the third phase.
He noted that phase one, which was estimated to take 460 working days, will conclude at the end of Jun next year. Phase two works are estimated to take some 550 working days and are commencing now.
The third and last phase is the most time-consuming, taking at least 650 working days to conclude.
